Safety razors and blade units therefor

ABSTRACT

A safety razor head comprises a head frame (101) carrying a cap member (104) and two blade units (105) all mounted in slots in end walls (103) of the frame (101) so as to be movable vertically, i.e. towards and away from the base (102) of the frame. The movable elements are urged upwardly by springs (106). The blade units (105) comprise metal pressing (108) of inverted L-shaped cross-section. Blade members (107) are attached to the top limbs (109) and guard portions (111, 112) are spaced forwardly of the blade edges (107A). The pressing (108) has projecting ears (114) at opposite ends by which each unit is mounted in the frame (101) for limited pivotal movement about an axis parallel with and close to the blade edge (107A).

This invention relates to safety razors and to blade units forincorporation in safety razors.

The invention aims at the provision of a safety razor having a highdegree of "conformance", that is to say the ability to permit orconstrain the skin-engaging elements of the razor to maintain optimumcontact with the varying contours of the skin during a shavingoperation.

In accordance with a feature of the present invention, a blade unit fora safety razor comprises a blade having a sharpened cutting edge and ablade support comprising a platform to which the blade is attached withits edge projecting forwardly of the platform, characterized in that thesupport further comprises an integral guard portion spaced forwardly ofthe blade edge, and mounting means on the support by which the integralguard and blade are mounted in use in a razor head, for rotationtogether about an axis parallel with and close to the blade edge.

The invention also includes a safety razor including a head frame inwhich at least one such blade unit is mounted for rotation about thesaid axis.

Preferably, the (or each) unit is also mounted for movement relative tothe frame under forces encountered during shaving, against the action ofa resilient restoring force, in directions transverse (i.e.substantially perpendicular) to a notional plane containing the bladeedge and a skin engaging surface of the guard portion.

A blade unit and safety razor head frame in accordance with theinvention and some modifications thereof, will now be described, by wayof example, with reference to the accompanying drawings, in which:

FIGS. 1 and 2 are perspective views of an end portion of the head frameand of a blade unit, respectively;

FIG. 3 is a cross-section taken at the sectioning line in FIG. 1,showing the blade units and a cap member in the normal positions ofrest;

FIG. 4 corresponds with FIG. 3, and shows the parts in differentrelative positions;

FIG. 5 is a diagrammatic cross-section illustrating different positionsof the cap and blade units in use;

FIG. 6 is an exploded perspective view of a modified razor head frameand blade units; and

FIG. 7 is a cross-section of the head frame of FIG. 6, correspondingwith FIG. 5.

The razor head shown in FIGS. 1 to 4 comprises a metal or mouldedplastics head frame 1 having an elongate base 2 and upstanding end walls3 at opposite ends thereof. Only one end of the frame is shown in theseFigs. the opposite end being a mirror image.

The head frame supports a cap member 4, two blade units 5 and threepairs of cantilever wire springs 6, whose inner ends (not shown) aresecured to the medial portion of the elongate base.

Each blade unit 5 consists of a narrow blade 7, having a sharpenedcutting edge 7A, and a blade support 8 formed as an L-shaped metalstamping to provide a platform 9 and a guard portion providing a curvedskin engaging guard surface 11 and a depending leg 12. The support has aslot 13 over most of its length to form a space between the platform 9and the guard portion and the blade 7 is securely attached to theplatform with its edge 7A projecting forwardly into that space,forwardly of the platform.

At its ends, the support 8 is formed with upwardly offset, projectingears 14 which are abuttingly engaged from below by upstanding endportions 6A of the wire springs 6.

The cap member 4 consists of a channel shaped support 16 in which a capmoulding 17 is secured.

The cap member and blade units are captured at their ends in recessesformed in the end walls 3 of the head frame. More specifically, the ears14 of the blade supports engage in narrow vertical slots 18 which alsoreceive the vertical end portions 6A of the respective wire springs.Alongside each slot 18 is a shallower, wider recess 19 whose forwardface 21 acts as a stop for the adjacent end of the respective leg 12.

Thus, each blade unit is guided for vertical movement in the head frameby engagement of its ears 14 in the slots 18. The springs 6 arepre-stressed so that in the normal, rest position, the blade units areheld by the springs in their outermost positions, as shown in FIG. 3.The spring ends 6A are guided and constrained for vertical movement intheir respective slots 18 and are pointed at their upper ends, wherethey engage the ears 14 so as to provide fulcrums, permitting rotationalmovement of the units about axes parallel with and close to thecutting-edges of the respective blades. As best illustrated in FIG. 4,this rotational movement is limited by engagement of the ends of thelegs 12 with the rear faces of slots 18 and the forward faces 21 ofrecesses 19, respectively. The cap member 4, which is set behind theblade units in the shaving direction, is constrained and guided forvertical movement only, parallel with the corresponding movement of theblade units. The cap member is also urged to its outermost position byits respective wire springs 6, as shown in FIG. 3.

FIG. 4 shows the moving parts in their innermost positions, in whichtheir springs 6 are "bottomed" against the base 2 of the frame.

In use of the razor, the cap and blade units are able to conform closelyto the differing contours of the skin areas being shaved by virtue oftheir being able to move, independently of each other and against theresilient restoring forces of their springs, according to the forceswhich they experience. This independence of motion is known in itselfbut, significantly, the blade units are also able to pivot freely inorder to permit each unit to maintain close contact with the skin atboth its cutting edge 7A and its skin engaging guard surface 11, thuspreserving its optimum attitude in spite of variations in the contoursof the skin surface. This is due to the fact that the pivotal axis ofeach unit is parallel with and just ahead of the sharpened edge of theblade.

In FIG. 5, the variations in skin contours are exaggerated to illustratethe way in which the moving parts of the razor accommodate undulationsin the skin surface and in particular how the attitudes of the bladeunits are adjusted automatically to maintain the desired contact withthe skin.

The translational movement of the units is described above as being"vertical". This, of course, assumes a specific attitude of the razorhead. The sense of the requisite movement, regardless of the attitude ofthe razor, is transverse to a notional plane containing the blade edgeand the skin engaging surface of the guard portion.

Because of the self-guarding nature of the blade units, it willgenerally be unnecessary to provide a separated guard member, but if oneis provided, it can be mounted for translational movement, with a springsuspension, in the same manner as the cap member.

The razor could of course have a single blade unit or three or more ifdesired, but two units are presently regarded as optimal.

FIGS. 6 and 7 illustrate a modified form of blade unit and head framewhich are generally similar to the above described embodiment but withsome structural modifications, principally as described below. Parts ofthe modified embodiment are given reference numerals increased by 100compared with the numerals used for corresponding parts in the firstembodiment.

The blade units 105 are virtually identical with these first described,save that the ears 114 are in the same plane as the guard portion ratherthan being upwardly offset. As a result the pivotal axis `A` of the unitis set lower than in the first embodiment.

The moulded head frame 101 is of a different construction, beingprovided in known manner with depending legs 122 by which the frame isadapted for releasable mounting on the upper end of a razor handle withlimited freedom to pivot, relative to the handle, about a longitudinalaxis.

The upper surface of the base 102 is formed with an upstanding pip 102Adestined to provide an integral rivet for securing a metallic springmember comprising a rectangular medial portion 106A having integralspring fingers 106 extending longitudinally away, and also upwardly fromthe plane of the portion 106A.

The rear wall of the frame 101 is formed with a channel to receive thecap moulding 117 in a fixed position.

In the end walls 103 of the frame, the slots 118 and recesses 119 arecompletely open from above and separate clips 123 are provided forretaining the blade units by their ears 114, to the frame.

The function and operation of the blade units is as described above.

I claim:
 1. A razor head comprising:a razor head frame including aunitary molding having an elongated base with upstanding walls atopposite ends thereof, the inner faces of said walls being formed withslots; at least one blade unit supported in said frame and having:ablade having a sharpened cutting edge; a blade support having a platformto which said blade is attached with its edge projecting forwardly ofthe platform; an integral guard portion having a skin engaging guardsurface spaced forwardly of said blade edge; and mounting means on saidblade support by which the integral guard portion and blade are mountedin said frame for rotation together about an axis parallel with andclose to said blade edge, said mounting means being received in saidslots for substantially vertical movement relative to said frame; saidslots being formed substantially in directions transverse to a notionalplane containing said blade edge and said skin engaging surface of saidguard portion; spring means engaging opposite ends of said bladesupport, said blade support ends being displaceable relative to saidframe, said spring means bearing on said elongated base and bearingupwardly at its ends on said mounting means to provide a resilientrestoring force; and the inner faces of said walls also being formedwith forward and rear abutment faces for engagement by portions of saidblade support to limit rotation of said support, wherein said blade unitis substantially vertically movable relative to said frame under forcesencountered during shaving, against the resilient restoring force, indirections transverse to the notional plane containing said blade edgeand said skin engaging surface of said guard portion.
 2. A razor headcomprising;a frame having an elongated base and upstanding side wallsdisposed on opposite ends of said elongated base, each of said sidewalls having recesses in their oppositely facing inner surfaces; atlease one blade unit supported in said frame and having:a blade with asharpened cutting edge extending generally parallel to the length ofsaid frame base; a blade support having a platform for holding saidblade and an integral guard portion having a skin engaging guard surfacespaced forwardly of said blade edge; and mounting means on said bladesupport by which the blade and guard portion are mounted in saidrecesses for rotation together about an axis parallel and close to thesaid blade edge and for substantially vertical movement within saidrecesses; and further including springs disposed on said frame andhaving a first portion in contact with the said frame and a secondportion in contact with said blade unit to bias said blade unit to moverelative to the frame in a direction generally perpendicular to the skinengaging surface of the guard portion.
 3. A razor head according toclaim 2, wherein the said blade support is of generally L-shapedcross-section, having one leg constituting the said platform and asecond, depending leg spaced forwardly of the blade edge, the said guardsurface being formed by a transitional portion between the legs of thesupport.
 4. A razor head according to claim 2, wherein the said bladesupport is of generally L-shaped cross-section, having one legconstituting the platform and a second, depending leg spaced from theblade edge for limited rotation about the said axis.
 5. A razor headaccording to claim 2, wherein the support is formed at its opposite endswith a pair of projections, extending beyond respective ends of the saidplatform and which constitute the said mounting means.
 6. A razor headaccording to claim 2, wherein the said blade support is formed as aunitary metal stamping.